Dermatomyositis and lupus are autoimmune conditions that may share symptoms like skin rashes, muscle weakness, and chronic inflammation. Dermatomyositis may involve lung complications and skin ulcers, while lupus causes a butterfly-shaped facial rash.

Dermatomyositis and lupus are separate diagnoses that may require a comprehensive medical exam and some testing to detect differences.

Dermatomyositis often leads to muscle weakness and reddish or purplish skin rashes. Lupus usually involves inflammation in the joints, skin, and internal organs.

The symptoms of dermatomyositis and lupus can sometimes overlap, making it challenging to differentiate the two conditions.

Both are autoimmune diseases that affect multiple organs and involve some degree of fatigue, muscle weakness, and skin irritation. “Autoimmunity” means the immune system fights the body’s own tissues because it mistakes them for harmful invaders.

Dermatomyositis

Common symptoms of dermatomyositis include:

  • Gottron papules: These are discolored bumps that may develop over knuckles, elbows, and knees.
  • Skin ulcers: Pustules and ulcers may develop in feet and hands for some people.
  • Muscle weakness: Proximal muscles (e.g., shoulders, hips) are often affected, making movements like standing up or raising arms difficult.
  • Fatigue: Generalized tiredness and weakness are common.
  • Joint pain: Inflammation in joints often leads to persistent pain or discomfort.
  • Calcinosis: This refers to an accumulation of deposits of calcium that cause hard, painful bumps under the skin or muscles, especially in children.
  • Difficulty swallowing (dysphagia): In some cases, dermatomyositis affects muscles in the esophagus, causing difficulty with swallowing.
  • Lung complications: In severe cases, interstitial lung disease can develop, causing breathing issues.

Lupus

Common symptoms of lupus include:

  • Butterfly-shaped facial rash: The most telling skin sign of lupus is a red rash that develops across the cheeks and nose, often triggered by sun exposure. It resembles a butterfly shape.
  • Joint pain and swelling: Lupus typically causes painful joints in the hands, wrists, and knees. Stiffness is also common.
  • Fatigue: Rest or sleep do not usually relieve chronic tiredness in lupus.
  • Photosensitivity: A sensitivity to sunlight often causes rashes to flare.
  • Kidney issues: Inflammation of the kidneys may affect their function and potentially lead to permanent damage.
  • Chest pain: Inflammation in the lining of the heart or lungs may translate into chest discomfort or pain.
  • Cognitive difficulties: Memory loss or confusion, sometimes called “lupus fog,” affects many people with the condition.

Yes, it’s possible to have both lupus and dermatomyositis, though this is relatively uncommon.

If you have both conditions, you may notice specific rashes associated with dermatomyositis, like Gottron papules, along with symptoms of lupus, such as a butterfly-shaped rash across the face.

In a 2023 case series including eight individuals with both lupus and dermatomyositis, seven of them initially received a lupus diagnosis (mostly cutaneous lupus erythematosus) and later developed dermatomyositis.

The eighth person had dermatomyositis first and then developed lupus after receiving a specific immune-modulating therapy for a separate condition.

In a 2016 case study, a person with dermatomyositis later developed systemic lupus erythematosus (SLE).

Dermatomyositis symptoms included skin ulcers and pustules on the palms and soles along with lung involvement. Within a year, lupus signs emerged, and diagnostic tests, along with kidney issues, confirmed lupus nephritis.

Researchers concluded that this suggests immune dysfunction in dermatomyositis may have contributed to the development of lupus.

COVID-19 as a trigger for dermatomyositis/lupus overlap syndrome

Research is very limited and nonconclusive regarding the link between COVID-19 and lupus and dermatomyositis.

However, some studies suggest that COVID-19 can potentially trigger the onset or worsening of autoimmune diseases, including dermatomyositis and lupus.

In a 2021 case study, a 58-year-old woman developed both dermatomyositis and lupus after having COVID-19. This is known as overlap syndrome. It refers to a condition in which a person has core symptoms of two or more autoimmune diseases simultaneously.

The woman experienced muscle weakness, characteristic skin changes such as rashes, and cardiac complications, including myopathy.

Overlap syndrome poses diagnostic challenges, as symptoms of dermatomyositis and lupus may be worsened or mistaken for COVID-19-related complications.

In this case, treatment included:

  • glucocorticoids to reduce inflammation
  • methotrexate to control the autoimmune response
  • hydroxychloroquine to manage symptoms

Treatment options for dermatomyositis and lupus typically involve the management of chronic inflammation and decreasing the immune response.

Medications commonly used in both conditions include the following:

  • Corticosteroids, such as prednisone, are the first line of treatment for acute symptoms or flare-ups. They also help improve muscle strength and manage skin rashes. However, long-term use requires caution due to side effects.
  • Immunosuppressants, like methotrexate and azathioprine, suppress the immune system and may prevent condition flare-ups.
  • Hydroxychloroquine is effective for managing lupus skin symptoms and inflammation.
  • Biologics, such as rituximab and tofacitinib, target specific immune system components. Doctors may use them in difficult-to-treat cases.
  • Physical therapy may help address muscle weakness from dermatomyositis.

Dermatomyositis and lupus can sometimes occur at the same time, creating what’s known as overlap syndrome. This means symptoms may be similar or may happen in the same areas. For example, skin rashes, muscle weakness, and joint pain can occur in either condition.

However, dermatomyositis and lupus are different conditions. Doctors may need to perform a comprehensive medical exam and order specific tests to tell them apart.